#include <TFT_eSPI.h> // Graphics and font library for ST7735 driver chip
#include <SPI.h>

TFT_eSPI tft = TFT_eSPI(); // Invoke library, pins defined in User_Setup.h

uint32_t targetTime = 0; // for next 1 second timeout

byte omm = 99;
bool initial = 1;
byte xcolon = 0;
unsigned int colour = 0;

static uint8_t conv2d(const char *p)
{
  uint8_t v = 0;
  if ('0' <= *p && *p <= '9')
    v = *p - '0';
  return 10 * v + *++p - '0';
}

uint8_t hh = conv2d(__TIME__), mm = conv2d(__TIME__ + 3), ss = conv2d(__TIME__ + 6); // Get H, M, S from compile time

void setup(void)
{
  tft.init();
  tft.setRotation(1);
  tft.fillScreen(TFT_BLACK);

  tft.setTextColor(TFT_YELLOW, TFT_BLACK); // Note: the new fonts do not draw the background colour

  targetTime = millis() + 1000;
}

void loop()
{
  if (targetTime < millis())
  {
    targetTime = millis() + 1000;
    ss++; // Advance second
    if (ss == 60)
    {
      ss = 0;
      omm = mm;
      mm++; // Advance minute
      if (mm > 59)
      {
        mm = 0;
        hh++; // Advance hour
        if (hh > 23)
        {
          hh = 0;
        }
      }
    }

    if (ss == 0 || initial)
    {
      initial = 0;
      tft.setTextColor(TFT_GREEN, TFT_BLACK);
      tft.setCursor(8, 52);
      tft.print(__DATE__); // This uses the standard ADAFruit small font

      tft.setTextColor(TFT_BLUE, TFT_BLACK);
      tft.drawCentreString("It is windy", 120, 48, 2); // Next size up font 2

      // tft.setTextColor(0xF81F, TFT_BLACK); // Pink
      // tft.drawCentreString("12.34",80,100,6); // Large font 6 only contains characters [space] 0 1 2 3 4 5 6 7 8 9 . : a p m
    }

    // Update digital time
    byte xpos = 6;
    byte ypos = 0;
    if (omm != mm)
    { // Only redraw every minute to minimise flicker
      // Uncomment ONE of the next 2 lines, using the ghost image demonstrates text overlay as time is drawn over it
      tft.setTextColor(0x39C4, TFT_BLACK); // Leave a 7 segment ghost image, comment out next line!
      // tft.setTextColor(TFT_BLACK, TFT_BLACK); // Set font colour to black to wipe image
      //  Font 7 is to show a pseudo 7 segment display.
      //  Font 7 only contains characters [space] 0 1 2 3 4 5 6 7 8 9 0 : .
      tft.drawString("88:88", xpos, ypos, 7); // Overwrite the text to clear it
      tft.setTextColor(0xFBE0);               // Orange
      omm = mm;

      if (hh < 10)
        xpos += tft.drawChar('0', xpos, ypos, 7);
      xpos += tft.drawNumber(hh, xpos, ypos, 7);
      xcolon = xpos;
      xpos += tft.drawChar(':', xpos, ypos, 7);
      if (mm < 10)
        xpos += tft.drawChar('0', xpos, ypos, 7);
      tft.drawNumber(mm, xpos, ypos, 7);
    }

    if (ss % 2)
    { // Flash the colon
      tft.setTextColor(0x39C4, TFT_BLACK);
      xpos += tft.drawChar(':', xcolon, ypos, 7);
      tft.setTextColor(0xFBE0, TFT_BLACK);
    }
    else
    {
      tft.drawChar(':', xcolon, ypos, 7);
      colour = random(0xFFFF);
      // Erase the old text with a rectangle, the disadvantage of this method is increased display flicker
      tft.fillRect(0, 64, 160, 20, TFT_BLACK);
      tft.setTextColor(colour);
      tft.drawRightString("Colour", 75, 64, 4); // Right justified string drawing to x position 75
      String scolour = String(colour, HEX);
      scolour.toUpperCase();
      char buffer[20];
      scolour.toCharArray(buffer, 20);
      tft.drawString(buffer, 82, 64, 4);
    }
  }
}
